There is obviously a fare war for Europe between Delta and United out of Boston. Delta has low fares to Germany and Switzerland, attacking Star Alliance airports for Lufthansa and Swiss Air. United, Swiss and Lufthansa have Amsterdam, France and Italy on sale attacking KLM, Air France and Alitalia airports.
Boston has low fares in the $600s across several countries in Europe from both Delta and United for travel departures November 2016 to March 2017. I used Google Flights and blocked WOW fares from the search to see where there are low fares from mostly major carriers.
Google Flights map of Europe with WOW Air flights blocked. Boston to Paris $648 Air Canada November 6-14.
Other fares seen on this map are likely near low fares for the season November-March 2017.
United low fares to Delta/Skyteam Alliance cities
- Boston – Amsterdam $623 United (KLM land)
- Boston – Milan $637 United (Alitalia land)
- Boston – Paris $648 Air Canada (Air France land)
- Boston – Rome $650 United (Alitalia land)
- Boston – Naples $654 Lufthansa (Alitalia land)
- Boston – Nice $660 Swiss (Air France land)
Delta low fares to United/Star Alliance cities
- Boston – Zurich $639 Delta (Swiss land)
- Boston – Brussels $661 Delta (Brussels Airlines land)
- Boston – Geneva $676 Delta (Swiss land)
- Boston – Munich $683 Delta (Lufthansa land)
- Boston – Frankfurt $697 Delta (Lufthansa land)
- Boston – Hamburg $714 Delta (Lufthansa land)
I have not seen any signs yet of American Airlines jumping into this battle over Europe. But, American was about 12 hours behind Delta and United last week in lowering their fares to Europe. Still no signs of $600s to Europe from West Coast airports either.